On Sunday, February 16, 2025 at 3:33:29 PM UTC-7 Alan Grayson wrote:
I got into a fairly heated argument with a Ph'D in physics from Brent's alma mater, the University of Texas at Austin, concerning the construction of the tangent vector space in GR. For this and other reasons we are no longer in communication. He insisted on including particle paths of all velocities passing through a point P on the spacetime manifold, aiming to construct the tangent vector space at P. I objected since this would violate one of the basic postulates of GR, which preclude particles assumed to be exceeding light speed. I was berated for making such a criticism. Initially I thought these faster than light speed particles were needed to form a *vector space*, in order to satisfy the linear additive property of a vector space under the field of real numbers. But suppose these vectors are constrained to be added relativistically, so no pair when added, can exceed light speed. Will this be sufficient to satisfy the linear additive property of vectors in a vector space, without violating the postulate of GR precluding faster than light speed particles? TY, AG Since the LT is linear, I think it will work to restrict the velocities on the tangent space to less than light speed. I'm puzzled why the physics guru from the U of Tx adamently objected to my criticism and implied simple fix for his obvious error. AG -- You received this message because you are subscribed to the Google Groups "Everything List" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion visit https://groups.google.com/d/msgid/everything-list/16b0e331-f115-4264-9ed9-f2e7d679175fn%40googlegroups.com.
